Photographic processing compositions



United States Patent 3,255,008 PHOTOGRAPHIC PROCESSING COMPOSITIONS William J. Telft, Crystal Lake, Ill., assignor, by mesne assignments, to Morton International, Inc., a corporation of Delaware No Drawing. Filed Oct. 13, 1961, Ser. No. 144,855

Claims. (Cl. 96-61) This application is a continuation-in-part of my copending application Serial No. 1,869, filed January 12, 1960, and now abandoned.

This invention relates to the production of photographic processing compositions and more particularly to developing-fixing monobath solutions for photographic halide emulsions.

The conventional prior art processes for the development of latent images on silver-halide photographic emulsions usually involves a multistep procedure, including development, hardening, short stopping, fixation, and washing at various intervals throughout and at the termination of the process. In view of these difiiculties there have been developed, over a relatively recent period, a number of so-called mono-bath solutions which provide, in a single formulation, the means whereby development and fixation of the latent silver-halide image may be carried out concomitantly in a single step.

While these latter monobath compositions have been satisfactory to a degree, they do not provide the flexibility and broad application that is desirable to carry out the single step, high speed development and fixation of exsilverposed photographic silver-halide emulsions to produce aproduct having a relatively broad and useful density range.

The most obvious advantages for monobath solutions are in the rapid and simple preparation of X-ray films, particularly dental X-rays, microfilm for record copying, and in general military applications. It would also be advantageous to provide a composition adapted to the rapid and high quality development and fixation of commercial emulsions, such as movie film, amateur photographic fiims, and printing or enlarging papers.

Accordingly, it is an object of the present invention to provide a photographic silver-halide emulsion developing and fixing composition which is capable of carrying out the fixing and developing operation at a relatively high speed at conventional temperatures in a single processing solution.

A further-object is the provision of a monobath developing and fixing solution which will produce fixed silverhalide photographic images having a broad density range and low base-fog characteristics.

A further object is the provision of a developing-fixing solution having low stain characteristics.

A still further object is the provision of a developingfixing solution which has a high processing capacity and an extended storage life.

A still further object is the provision of a developingfixing solution particularly adapted to the rapid processing of X-ray film and microfilm, said solution producing high gamma in such films.

A still further object is the provision of a developingfixing solution which is applicable to a broad range of silver-halide emulsion photographic papers and films.

These and other objects of the present invention may be more readily understood by reference to the following specification and claims.

In one broad form the present invention relates to photographic silver-halide emulsion developing and fixing composition containing a silver halide developer, a

compound selected from the group consisting of ammonia and substituted amines and a compound selected from the group consisting of thioglycollic acid, fi-mercaptopropionic acid, mercaptosuccinic acid and 3-mercapto-1,'2-propanediol. It should be understood of course that when reference is made to the acids referred to above, such compound is present in the solution in the ionized form together with the ionized ammonia or substituted amine radical. Thus the acids of the aforementioned group are present as ammonium salt or substituted ammonia salts as typified by the amines.

The ammonium thioglycolate or substituted ammonium thioglycolates may be readily incorporated into the compositions of the present invention as such, or may also be formed in situ by the addition of ammonium hydroxide, or an amine of the type described, to a prepared solution containing thioglycollic acid, or an inorganic thioglycolate salt, such as, for example, sodium thioglycolate, the only requirement being that the thioglycolate ion and the substituted amine or ammonium ion be present concomitantly in the processing solution. The amine material, therefore, may be present in equimolar proportions with respect to the thioglycolate ion, or alternatively, may be present in greater or lesser proportions. For example, in the most preferred aspects of this invention, the ammonium ion may be present in a mole ratio of from about 30 to about percent of the thioglycolate ion. The thioglycolate ion is preferably present in the solution in a concentration of from about 1 to about 3 percent.

The substituted amines present per se or as salts of thioglycollic or the other named acids, are preferably those derived from water soluble amines, such as lower alkyl substituted amines and hydroxy lower alkyl substituted amines. The organic substituents in the foregoing substituted amines in the most preferred aspects of the invention each contain up to about 3 carbon atoms. Exemplary of the types of amine salts which are contemplated for use in these compositions are those derived from monomethylamine, dimethylamine, diisopropyl amine, di ethylamine, monoisopropanolamine, dii'sopropanolamine, and triethanolamine, and the like.

It should be understood that While particular reference is made to the above thioglycolates, the foregoing is also applicable to mercaptosuccinic acid and fi-mercaptopropionic acid.

the present invention contain a silver-halide developer, the

most preferred being selected from the group consisting of hydroquinones and catechol.

It is also a preferred aspectof this invention to utilize in conjunction with the aforesaid silver-halide developer a developing initiator of which the most preferred is pmonomethylaminophenol (sold as the acid sulfate salt under the trade name Metol), and 1-phenyl-3-pyrazolidone (sold under the trade name Phenidone).

In addition to the foregoing above described compounds it is also desirable in many instances to include in the present photographic processing solutions conventional additives, as for example, restrainers, such as sodium bromide and developer stabilizers, such as sodium sulfite.

The following examples will illustrate the preparation of specific embodiments of the claimed compositions and in addition will illustrate the effectiveness of the particular solutions in the processing of standard exposed strips of photographic film.

Example 1 Ammonium thioglycolate developing-fixing solution.---- The following example will illustrate the preparation of a units.

monobat-h solution of the present invention utilizing ammonium thioglycolate:

Grams Phenidone 6 Hydroquinone 48 Sodium sulfite 161 Ammonium thioglycolate (67%) (56% as thioglycollic acid) 90 Sodium bromide 6 7 Potassium metabisulfite 20 Sodium hydroxide Approx. 45 Water to make 1 liter.

{To pH 10.5.

The above formulation, representing a concentrate, is diluted with 2 liters of distilled water to produce a working strength solution. Standard film strips pre-exposed on an Eastman Kodak Sensitometer, Type IIB, and obtained from the Remington RandCompany of DuPont Microfilm, were processed for 30 seconds by placing the same in the solution maintained at 90 F. The film was removed after the processing and washed for 30 seconds. The

determined on an Ansco-Sweet Densitometer Model #11. The readings obtained were a base fog of 0.30 unit and a maximum density of 1.77. The usable density range was obtained by subtracting the maximum density from the base fog, producing in this instance a range of 1.47

' Example 2 Mnoisopropanolammon-ium thioglycolate.-A composition identical with that set forth in Example 1 was prepared, using however, monoisopropanolammonium thioglycolate (90 grams) in place of the ammonium thioglycolate. Test film strips of Du Pont microfilm were processed in the working strength solution (diluted with water to make 3 liters) for 30 seconds at 90 F. As determined on the Ansco-Sweet densitometer, the base fog was 0.22 unit and the maximum density was 1.18 units.

Example 3 Diisopropanolammonium thi0glyc0late.This example was the same as Example 1, utilizing however diisopropanolammonium thioglycolate in place of ammonium thioglycolate in the manner set forth in Example 2. A Du Pont microfilm processed for a period of 30- seconds at 90 F. shows a base fog of 0.1 unit and a usable density of 1.53 units.

Example 4 T rr'etha n-olamine thio glycolirte.The processing solution was identical with that set forth in Example 1, substituting however 90 grams of triethanolamine thioglycolate for ammonium thioglycolate. Du Pont microfilm strips were developed for a period of 1 minute at 90 F. The film strips had a base fog density of 0.26 and a maximum density of 2 units. The usable density was 1.74 units.

Example 5 Mercwptosuccinic acid.-A composition of the type set forth in Example 1 was prepared, using however 64.5 grams of mercaptosuccinic acid and 30 grams of ammonium chloride in place of the 90 grams of ammonium thioglycolate. Test film strips of Du Pont microfilm were processed in the working strength solution (diluted with water to make 3 liters) for 60 seconds at 85 F. As determined on the Ansco-Sweet densitometer, the base fog was 0.59 unit and the maximum density was 1.97 units.

Example 6 fi-Mereaptopropionic acid.-A composition identical with that set forth in Example 1 was prepared, using however ,B-mercaptopropionic acid, 60 grams, and ammonium chloride, 30 grams, in place of the 90 grams of ammonium thioglycolate. Test strips of sensimetrically exmaximum density range of the film and the base fog were 4 posed film were processed in working strength solution (diluted With water to make 3 liters) for 60 seconds at F. As determined on an Ansco-Sweet densitometer, the base fog was 0.29 unit, and the maximum density 2.06 units.

Example 7 3-mercapto-2J-propanediol.-A composition identical with that set forth in Example 1 was prepared, using however 3-mercapto-l,2-propanediol, 60 grams, and ammonium chloride, 30 grams, to replace the grams of ammonium thioglycolate. Test strips of exposed films were processed in working strength solution for 60 seconds at 85 F. As determined on an Ansco-Sw-eet densitometer the base fog was 0.41 unit and the maximum density 2.02 units.

The foregoing examples illustrate various combinations of ingredients and the effect of varying the type of amine thioglycolate utilized in the processing bath. As previously stated, similar results may be obtained utilizing Metol in place of Phenidone as a developing initiator. The Phenidone concentration in preparing a concentrate, such as described in Example 1, may vary from between about 5 to about 7 grams per liter, with the optimum being approximately 6 grams per liter. Likewise the concentration of hydroquinone will vary from about 45 to 58 grams per liter with 4.8 grams per liter being optimum. When Metol is used in conjunction with hydroquinone, the Metol concentrate will contain from about 45 to about 90 grams per liter with about 70 grams being optimum. Of course, working strength solutions are at about onethird the concentrations indicated.

The photographic developing and fixing solutions may also be prepared from dry compositions using a thioglycolate or other acid salts, such as sodium thioglycolate and as a source of thioglycolate ion when preparing the working solution and an ammonium salt, such as ammonium chloride or an amine, as a source of the ammonium or substituted ammonium ion. Such dry compositions are also contemplated as a part of the present invention.

Development of silver-halide emulsions, usingthe compositions of this invention, is preferably carried out at temperatures between about 70 and 110 F. It should be understood that the development times for the processing solutions of the present invention are relatively short. At the higher temperatures (such as about F.) the processing time is about 20 seconds, and at the lower limit of the preferred temperature range about 75 seconds.

It has also been found that processing of films may be carried out for periods of time in excess of that required to develop and fix the latent image of exposed films Without deleterious effect. Thus, for example, comparably exposed sensitometric strips of microfilm were developed in one monobath solution of the present invention at 80 F. for periods of time ranging from 30 seconds to 1 hour without any indication of a. gain or loss of density at either end of the strips. Extended immersion of the exposed films in the processing solutions does not change the photographic quality of the result produced, although it should be understood that, as is the case with all aqueous processing solutions, extended soaking Will result in undesirable swelling and soft-eningof the gelatin emulsion.

It has also been found that the developing-fixing solutions of the present invention produce a finished film when processed as indicated, with the emulsion hardened to a degree comparable with conventional (multi-solution) processing.

The washing required after processing is variable with the type of emulsion. Accordingly, enlarging and printlng papers and thin emulsion films, such as microfilm, require only a few minutes washing for adequate storage life. Films with a heavier emulsion, such as, for example, X-ray films, can be washed for a period of up to about 5 minutes for maximum storage stability.

A further advantage which may be seen in photographic processing compositions of the present invention is that they do not produce the degree of sludging ordinarily observed in the use of conventional photographic developerfixer compositions and processing. The sludging of the processing bath is the result of reducing silver halide to metallic silver which latter forms a black deposit in the processing tanks and on the surface of the equipment used. In the developer-fixer compositions of the present invention the sludging is about 10% or less than that found in a comparable monobath using a thiosulfate fixer.

While several particular embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated, therefore, by the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention. a

I claim:

1. A photographic, silver-halide emulsion developing and fixing composition comprising an aqueous solution containing a silver-halide developer, a compound selected from the group consisting of ammonia and water-soluble substituted amines and a compound selected from the group consisting of thioglycollic acid, B-mercaptopropionic acid, mercaptosuccinic acid and 3-mercapto-1,2-propanediol.

2. The composition of claim 1 wherein each of said alkyl groups contain up to 3 carbon atoms.

3. The composition of claim 1 wherein the pH of the solution is from 9 to 11.5.

4. A dry composition for preparing a photographic silver-halide emulsion developing and fixing solution, said dry composition comprising a silver-halide developer, at thioglycolate salt, and an ammonium salt.

5. A dry composition for preparing a photographic silver-halide emulsion developing and fixing solution, said dry composition comprising a silver-halide developer, sodium thioglycolate and ammonium chloride.

6. The composition of claim 1 wherein the developer is selected from the group consisting of hydroquinone, catechol, p-monomethylaminophenol and 1 phenyl i 3- 'pyrazolidone.

References Cited by the Examiner UNITED STATES PATENTS 2,053,516 9/1936 Crabtree 96--66 2,614,927 10/1952 Broughton 9661 2,625,476 1/1953 Henn 96-66 2,834,676 5/1958 Stanley et al. 96-61 X OTHER REFERENCES Haist et al. (I), .Phot. Eng., 7, 1956, pages 182-189. Haist et al. (II), Photographic Science and Engineering, vol. 5, No. 4, July-August, 1961, pages 198-203.

Photo Lab. Index, vol. I Quarterly Supplement No. 12 (1942), pages 13-09, 13-10, Morgan & Lester, New York.

NORMAN G. TORCHI N, Primary Examiner.

A. D. RICCI, R. SMITH, Assistant Examiners. 

1. A PHOTOGRAPHIC, SILVER-HALIDE EMULSION DEVELOPING AND FIXING COMPOSITION COMPRISING AN AQUEOUS SOLUTION CONTAINING A SILVER-HALIDE DEVELOPER, A COMPOUND SELECTED FROM THE GROUP CONSISTING OF AMMONIA AND WATER-SOLUBLE SUBSTITUTED AMINES AND A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THIOGLYCOLLIC ACID, B-MERCAPTOPROPIONIC ACID, MEXCAPTOSUCCINIC ACIK AND 3-MERCAPTO-1,2-PROPANEDIOL. 